Interoperability Analysis of Two Different Coil Systems for Inductive Power Transfer

In order to establish inductive charging for electric vehicles (EV) in public places, interoperability between primary (charging stations) and secondary (vehicles) sides must be provided. This paper uses finite element analysis and network circuit analysis to compare two different coil systems regarding interoperability aspects, such as efficiency and maximum transferable output power for different positional offsets and air-gap classes with certain boundaries and limitations of the power electronics. To improve performance the influence of series adaptive capacitor tuning on these aspects is investigated as well. Furthermore, the magnetic leakage field distributions of the models are evaluated. It is shown that proper tuning of the primary side helps to increase interoperability due to the improvement of the power transfer capabilities in offset and reduction of coil currents and therefore reduce magnetic leakage fields.